LS1 Clutch & Shifter Upgrade - Bookin' By The Book

Some enthusiasts bemoan any attempts to "clean up" personal transportation. To them, the likes of PCV systems, catalytic converters, and EGR are all vestiges of government oppression to be cut out and discarded at the earliest opportunity.

Others justify similar actions not by disagreeing with their premise, but by arguing the contribution of the individual hot rodder (or the sum total of all in the enthusiast community) who eliminates emissions control devices is too small to make any significant difference.

As this is surely a touchy subject among GMHTP readers, we have always left-and will continue to leave-individual choices about your vehicle up to you. But there are facts to be faced. While it's true that today's cars emit far less pollution than those of decades past, there are so many on the roads of the world that the problem isn't going away. And as if traditional pollutants like hydrocarbons and oxides of nitrogen weren't enough, the world has finally begun to wake up to the scientific realities of carbon dioxide, a gas for which laws and regulations are clearly coming down the line at full tilt. Exactly how we'll get to the next stage of motor vehicle emission control in the United States is only starting to be seriously worked out, but the inevitable scenario that's headed down the pipe is this: emissions laws, and the enforcement thereof, will only get stricter.

This translates to additional concerns for aftermarket high-performance parts manufacturers and the consumers who install these parts on street-driven vehicles. (Even now, getting caught driving a car with compromised or eliminated emissions systems on public roads can often get you in some serious trouble with the law). But it's not all gloom and doom, because some of us have already had to operate under such a more-stringent scheme for quite some time.

3/27

Light Pewter Metallic isn't the color for everyone, but honestly, you'd have to paint a Camaro SS hot pink to make it ugly. We found this 61,000-mile example in excellent overall condition, with only minor flaws on the exterior (for example, the previous owner started pressure washing the driver-side front fender before realizing it was a bad idea-goodbye, clear coat).

California, Here We Come!For decades, enthusiasts in California have had to deal with that state's Vehicle Code Section 27156, which is summed up by the California Air Resources Board website (www.arb.ca.gov) as follows: "To ensure that [automotive emission control] systems operate as designed ...Section 27156 and the Federal Clean Air Act prohibit modifications that increase motor vehicle emissions. Since if properly designed, most performance modifications do not increase vehicle emissions, these same laws also allow the installation of parts or modifications proven by their manufacturers and the ARB not to increase vehicle emissions." If a part or modification is shown to not increase emissions, it is granted an exemption (called an Executive Order) allowing it to be installed on specific vehicles. This is where the "CARB E.O. #" advertised for many aftermarket parts comes from, and without it, a component can't be sold or used on a California vehicle. It's easily the strictest structure currently in existence for aftermarket parts in this country.

While what is to come in the future (both to California and the nation as a whole) will no doubt vary from this system as it currently exists, we at GMHTP have decided a project build in conformance with the CARB-mandated system is a great way to show that increased horsepower and emissions legality are not mutually exclusive, and that the joys of modifying and driving a personalized vehicle will continue to subsist no matter what challenges come next. That's right, a "modded muscle car for the new millennium" that can prove our hobby is here to stay. As an added bonus, we will not be sacrificing fuel economy in this build, and many of the parts we install will actually cut fuel consumption-assuming we can subdue the urge to use the extra power too often. (We should point out that some of the upgrades we'll be performing have nothing whatsoever to do with emissions laws, as is the case with the installs in this particular story. And as a final note, we're going to take one or two minor liberties by using some "factory performance" parts in future stories, components that we're certain would meet the criteria of the CARB E.O. system if tested-further explanation to come later).

Meet "CT"Before getting to our parts, we need to introduce our new project vehicle. Six-speed LS1 F-bodies are difficult to come by in most parts of the country, and this author had to trek to Vermont to grab the 1999 model seen here. Since it was stock, in great condition, and showed low mileage for its age-not to mention being offered for slightly below book value-it was a definite must-have. The fact that it was an SS only put the icing on the cake!

We're nicknaming this project car "CT" as a nod to its having been originally leased from a dealership in Connecticut. During baseline testing at Raceway Park, attempts at full passes were aborted when the clutch pedal stuck to the floor between shifts. Not ones to throw band-aid fixes onto project vehicles, we decided to install all-new clutch hydraulics-and if the old master and slave were coming out, so was the clutch. For this particular build, a very streetable clutch that could still deliver plenty of clamping power was in the cards. One of the best choices out there to fit these criteria comes from the General himself. Scoggin-Dickey Parts Center sells its LS7 Clutch Kit (PN SDLS7CK) for $459. This includes the appropriate flywheel, clutch disc, pressure plate, and new GM bolts. The company also provided us with new master (PN 12570277, $145) and slave (PN 15046288, $135) cylinders along with a new pilot bearing (PN 14061685, $16). Since the trans was coming out, it was the opportune time to replace the stock shifter. B&M provided us with its Precision Sport Shifter for T56-equipped F-cars (PN 45052), which sells for $208. To top it off, Speed Inc. was sourced for one of its Classic Shift Knobs (PN IZM1630016 for white), made in the U.S.A. and selling for just $24. Speed Inc. also hooked us up with a slave cylinder shim (PN IZM525, $14), the function of which we'll describe momentarily.

Check out the photo captions for the install. After all was said and done, we were rewarded with a clutch pedal with near-stock feel, very progressive engagement, and with absolutely zero chatter. The new hydraulics meant no more stuck pedals, either: back at Raceway Park, this author put down a 13.58 at 105.4 on a 2.16 60-ft (that's with bald street tires, mind you). The B&M shifter is fantastic too, with very precise feel and throw length that's just right. In our next installment, we'll begin our quest for more emissions-legal horsepower with aftermarket intake and exhaust systems, so be sure to pick up a copy of the July 2009 issue of GMHTP for the lowdown.

COMMENTS

related articles

In this edition of Technically Speaking, we walk a concerned reader through diagnosing and treating an evaporative emissions and "check engine" light issues. Check out our step-by-step EVAP-testing procedure. » Read More

Check out part 3 of our street legal 1999 Chevy Camaro SS as we upgrade the suspension and the rearend and still be able to pass smog in all 50 states. Only at www.gmhightechperformance.com, the official website for GM High-Tech Performance Magazine. » Read More

Our 1999 Chevy Camaro SS project vehicle is getting its intake and exhaust upgraded. We install a Edelbrock Tubular Exhaust System, a Edelbrock Cat-Back Exhaust System and a K&N Generation II Fuel Injection Performance Kit and still remain legal in all 50 states. Only at www.gmhightechperformance.com, the official site for GM High-Tech Performance Magazine. » Read More